Treesearch

A multiple linear regression model explains 90% of the variance in daily use of an urban recreation site. Explanatory variables include season, day of the week, and weather. The results offer guides for recreation site planning and management as well as suggestions for improving the model.

Female eastern spurce budworm larvae, Choristoneura fumiferana (Clemens) (Lepidoptera: Tortricidae), inoculated with a medium lethal spore dosage of the microsporidium. Nosema fumiferanae (Thomson) exhibited significant reductions in a consumptive index (CI), nitrogen consumptive index (NCI), relative growth rate (RGR), and gross(ECI) and net(ECD) production efficiencies when compared to microsporidian-free larvae. Diseased larvae also exhibited significant increases in approximate digestibility (AD), N utilization efficiency (NUE), and larval moisture content. Both healthy and diseased...

A standardized bioassay procedure was used to determine median lethal doses (LD 50) of the microsporidium, Nosema fumiferanae (Thom.), on newly molted fourth- and fifth-instar eastern spruce budworm larvae (Choristoneura fumiferana (Clem.)). The LD50 for fifth-instar larva was 1.23 x 106 2.82 x 105 spores. The fourth-instar LD50 was 2.23 x 104 4.30 x 103 spores per larva for populations experiencing prolonged post-diapause cold storage or an elevated temperature during diapause and 2.00 x 105 6.66 x 104 spores per larva for populations not experiencing stressful conditions during and after...

The third inventory of Indiana's timber resource shows that commercial forest area in the Knobs Unit decreased less than 2% between 1967 and 1986, from 1,769 to 1,741 thousand acres. During the same period growing-stock volume increased 33%. Highlights and statistics are presented on area, volume, growth, mortality, and removals.

Discusses production and receipts for 1986 and production for recent years in the Lake and Central States. Shows Michigan, Minnesota, and Wisconsin production by species for each county and compares production by Forest Survey Unit with that of previous years. Presents 1986 production and receipts data for Illinois, Indiana, Iowa, and Missouri, and shows four production classes by county.

The fourth inventory of the timber resource of Wisconsin shows that growing-stock volume increased from 11.2 to 15.5 billion cubic feet between 1968 and 1983, and area of timberland increased from 14.5 to 14.8 million acres. Presented are analysis and statistics on forest area and timber volume, growth, mortality, removals, and projections.

Discusses recent Michigan forest industry trends; production and receipts of pulpwood, saw logs, and veneer logs; and production of other timber products in 1984. Reports on logging residue, on wood and bark residue generated at primary wood-using mills, and on disposition of this mill residue.

Tall shrub dynamics were examined in upland stands in northern Minnesota. Mortality rates of shrub stems did not differ among the stands. Shrub stem regeneration did differ among the stands and was related to overstory characteristics, soil moisture, and soil nutrients. Stem density was regulated by annual regeneration.

It is often necessary to choose between several forestry projects. This paper provides the background needed to evaluate projects from a financial perspective. The basic steps for preparing a project analysis, suggestions for dealing with uncertainty, and techniques for monitoring a projects are presented.

Presents statistics on Indiana's growing-stock and sawtimber volumes by county for 1986. Includes map showing growing-stock volume distribution by county.